File photo taken on July 16, 2016 shows Donald Trump speaking during a campaign event in New York, the United States. (Xinhua/Li Muzi)
New York billionaire Donald Trump was officially declared as the U.S. Republican Party's presidential nominee on Tuesday.
U.S. House Speaker Paul Ryan officially announced Trump's nomination after a state-by-state vote.
"The chair announces that Donald J. Trump, having received a majority of these votes, entitled to be cast at this convention, has been selected as the Republican Party nominee for president of the United States," Ryan said.
The real estate mogul from New York clinched the nomination as party delegates from the country's all 50 states, five territories and Washington, D.C. cast their votes.
Trump's son Donald Trump Jr. announced New York's delegation votes, allowing his father to secure 1,237 delegate votes he needed to become the Republican presidential nominee.
"It is my honor to be able to throw Donald Trump over the top in the delegate count tonight," Trump Jr. said.
The Republicans also nominated Indiana Governor Mike Pence as Trump's vice presidential running mate.
The nomination came after a somewhat tumultuous first day of the Republican National Convention.
On Monday, anti-Trump supporters in the party failed to push through a roll call vote to change the event's rules, which would allow some of the delegates who had voted Trump to recast their votes to other candidates.
Trump's wife Melania was accused of plagiarizing a 2008 speech by First Lady Michelle Obama in her speech on Monday night.
